1. Field of the Invention
The present invention relates generally to a filament data link of a missile or other high speed vehicle and, more particularly, to an improved way of providing a filament pack on such a missile or other high speed vehicle so as to aid aerodynamic streamlining and not expose the filament to undesirable torsion, kinking or tension that could cause reduction in data transmission efficiency or filament breakage.
2. Description of Related Art
Many present day missiles on being launched are interconnected with the launch site by a length of filament via which navigational information is provided throughout a portion of or the entire path of travel. Such filaments, consisting typically of an optical fiber, must be dispensed from a wound pack carried on the missile or vehicle in such manner as not to subject the filament to torsions or excessive tensile forces that would reduce the efficiency of optical signal transmission or, in extreme cases, sever the link completely.
It is generally desirable to make the outer diameter of a wound filament dispenser as large as possible in order to accommodate the required length of filament with as few turns or windings as possible and thereby reduce the possibility of harming the filament. The aerodynamic designer, on the other hand, desires to reduce drag by having a streamlined fairing at the aft end of the craft fuselage. Also, it is important that the outer diameter of a conventionally wound filament bobbin be smaller than the exit passage through which the filament is to be dispensed, otherwise the filament can contact the exit walls which undesirably increases the tensile load on the fiber and would limit filament payout speed. Therefore, even with a full bodied diameter exit, this necessity for clearance within the dispenser shroud reduces the overall permissible winding diameter.